The London Stock Exchange has declined to publicly explain a two-hour IT problem experienced this morning on its network.
The exchange began to investigate a "network-related problem" on its Turquoise dark pool, or anonymous trading venue, at 8.25am, which it fixed by 10.30am. The problem meant traders could not use the market.
The news comes a day after the exchange delayed switching on the system on its main cash market, apparently for another two weeks, following testing. The system is billed as the fastest trading technology in the world, but is already facing fresh challenges from other major markets around the world.
The LSE runs a customised version of Linux for its matching engine, developed in a C++ environment and running through Cisco and Juniper switches.
It declined to say whether today's issue was a problem with the network hardware or software, the Millennium Exchange Linux trading system, or whether it was the result of human error such as incorrect connection or order code entry. A report would be provided to traders, it said, "in due course".
On its live service web portal, the LSE told traders it had halted the integrated and midpoint order books while it fixed the problem, asking them to "disconnect all applications". Some early morning trades had to be reordered.
After Turquoise launched in early October on the new system, it experienced an outage for around one hour. Analysts said that for a high-profile launch, the problem was significant but had been rectified quickly.
The LSE's previous Microsoft .Net -based trading system on its cash markets, called TradElect, experienced a day-long outage in 2007 as the result of networking problems.